1. Field of the Invention
The present invention relates to an application of a flash memory. More particularly, the present invention relates to a program management method of a flash memory, and a flash memory controller and a flash memory storage device using the same.
2. Description of Related Art
Generally, a flash memory chip in a flash memory storage device can be divided into a plurality of physical blocks, and each of the physical blocks can be divided into a plurality of physical pages. Wherein, the physical block is a minimum erase unit of the flash memory, and the physical page is a minimum program unit of the flash memory.
Since during a program operation of a memory cell of the flash memory, a value of the memory cell can only be programmed from 1 to 0, data cannot be directly written into the programmed physical pages. In other words, the page stored with data has to be first erased, and then the page can be re-programmed. However, since the erase operation of the flash memory is performed while taking the physical block as an erase unit, during the erase operation of the physical page stored with old data, the whole physical block where the physical page is belonged to have to be erased.
Due to characteristics that the physical page of the flash memory serves as the program unit, and the physical block serves as the erase unit, the physical blocks in the flash memory chip are approximately divided into a data area and a spare area. Wherein, the physical blocks of the data area are physical blocks that have been used to store data, and the physical blocks of the spare area are unused physical blocks. When a host is about to program data into the flash memory storage device, a control circuit of the flash memory storage device extracts a physical block from the spare area to program the data, and logically associates the extracted physical block to the data area. Moreover, after the physical block of the data area is erased, the erased physical block is logically associated to the spare area.
Nothing herein should be construed as an admission of knowledge in the prior art of any portion of the present invention. Furthermore, citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention, or that any reference forms a part of the common general knowledge in the art.